I was doing a 3-phase 277/480 ahu unit today, then the hvac guy tells me he needs a 110v outlet for his condensate pump. I tell the boss this he say come off the the 110 panel join the 277 pipe together to the disco then feed threw the disco for the 110. I know no feed through for panel, how about disco?
You end up back at 312.8 and you have to ask yourself IS "adequate space for this purpose is provided.". I would bet a couple of 12 or 14 guage wires are not going to put this cabinet over 40% of the available wiring space. (or 75% of the cross section where the wires run)
quote"It would be darn near imposable to overfill a panel with branch circuit wiring."
Boy in the 60's they sure knew how to do it. I go to a lot of jobs with old GE load centers so packed up with wire the cover almost springs off when the screws are loosened. Of course the # of wires is still comparable to modern stuff, it's just the boxes were so little, and the long spare length's left on the wires before terminating at the breakers makes for a big crowd.